This invention relates to lubricant compositions that include a mixture of antimony thioantimonate (SbSbS.sub.4) and antimony trioxide (Sb.sub.2 O.sub.3) dispersed in lubricating materials to impart extreme pressure (EP), antiwear and antiabrasive properties to the materials.
Antimony thioantimonate (SbSbS.sub.4) is known as a lubricant additive with outstanding EP and antiwear properties (U.S. Pat. No. 3,965,016 that issued June 22, 1976).
Such synergism is surprising as Sb.sub.2 O.sub.3 per se is not known to enhance lubricating properties of such lubricants. Moreover, significant economic advantages are provided by substitution of the low cost Sb.sub.2 O.sub.3 for the relatively expensive SbSbS.sub.4.
More specifically, this invention concerns lubricating compositions comprising a grease, a mineral oil of lubricating viscosity, a synthetic fluid of lubricating viscosity or a solid lubricant resin binder such as polyimide, polyphenylsulfide, etc., and a synergistic mixture (by weight) of from 0.1% to 20% of antimony thioantimonate (SbSbS.sub.4) and from 0.1% to about 20% of antimony trioxide (Sb.sub.2 O.sub.3). The SbSbS.sub.4 and Sb.sub.2 O.sub.3 mixtures are in a SbSbS.sub.4 /Sb.sub.2 O.sub.3 weight ratio in the range of 0.1 to 10.